The present invention relates generally to a connection structure between a watt-hour meter socket base and one or more plug-in type circuit breakers, also referred to as plug-on circuit breakers. It is known to those in the trade that the connection path must consist of an electrically conductive material. Very often insulated copper or aluminum cables are employed, requiring the use of tested and approved electrical wire connectors. These connectors require mounting fasteners, typically a bolt, spring washer, and nut. Additionally, the cable requires preparation. Namely the insulation must be carefully removed so as not to reduce the conductor cross section, and the wire must be shaped or formed so that its ends are cooperatively received by the aforementioned wire connectors.
Another known connection structure commonly employs the use of bus bars such as copper or aluminum with rectangular cross sections. As an example, a 200 A (ampere) circuit breaker connection using copper bus bar may have a cross section of 0.188 inch by 1.000 inch (0.48 cm by 2.54 cm) or an aluminum bus bar with a cross section of 0.250 inch by 1.000 inch (0.64 cm by 2.54 cm). This method requires various manufacturing operations, typically, cut to length, drilled or punched holes, and forming. Due to the rigidity of the bus bar, the forming must be very accurate to ensure alignment of the meter socket base and circuit breaker base. Furthermore, for a bus bar, an element must be added to receive the circuit breaker. The circuit breaker is typically mounted to a receiving spades or lugs 0.093 inch (2.36 mm) thick, thus requiring the use of an additional part and fasteners. Additionally, regulatory agencies require tin or silver plating be applied on areas where connections are made.
FIG. 1 shows a typical modern 200 ampere meter socket base assembly 200 connected by formed bus connectors 202 to a circuit breaker receiving assembly 204. The illustrated meter socket base assembly 200 is connected to copper bus bars 202, while opposite ends of the bus bars are connected to the circuit breaker receiving assembly 204. Load side meter socket jaws 206 are secured to the bus bars 202 and insulating bases 208 that provide the proper mounting height along with meter blade guides 210. The bus bars 202 are additionally secured to circuit breaker contact elements 211 by fasteners such as screws and corresponding nuts. The circuit breaker contact elements 211, including circuit breaker receiving blades 212, are secured to a breaker insulating base 215 by fasteners such as push-nuts 218. Note that the illustrated assembly 200 is comprised of 24 unique parts and a total of 49 parts.
FIG. 2 shows a typical modern 200 ampere meter socket base assembly 230 connected by formed wires 232 to a circuit breaker receiving assembly 234. The assembly 230 is similar to the assembly 200. The illustrated meter socket base assembly 230 is connected to the wires 232, while opposite ends of the wires are connected to the circuit breaker receiving assembly 234. Load side meter socket jaws 236 are secured by suitable fasteners to wire connectors 238 and insulating bases 240 that provide the proper mounting height. The wires 232 are secured to the wire connectors 238 with nuts and set screws 242. Opposite ends of the wires 232 are secured to circuit breaker contact elements 243, including spaced apart circuit breaker receiving spades 244, by connectors and set screw units 246. The circuit breaker contact elements 243 are secured to a circuit breaker insulating base 248 by fasteners such as push-nuts 250. Note that this construction is comprised of 24 unique parts and a total of 60 parts.
The prior art construction described above has disadvantages. First, the use of additional components acts to increase both material and labor costs. Second, the additional connections contribute to the heating of the device.